So you can do that with any fabrics and it won't damage them? I remember I did that with some kind of powdered detergent in college and the detergent discolored the clothes where I poured it on them.

You just add any additives into the detergent dispenser drawer in the main wash compartment. Water still gets washed through there when using TwinDos. At least the models available in Australia work this way. Hope this helps

STPP contact won't harm anything.

Jim - That's what I thought, but a Miele rep told me that that water that gets washed through the detergent tray when you're using TwinDos does not end up in the drum. It is drained directly out of the machine when you're using TwinDos. He said they had run a little experiment to verify that. So, presuming that is true, the STPP would be completely wasted if I put it in the detergent tray when using TwinDos.

What he said makes sense to me because I saw a YouTube video from Miele that talks about how water is always put through the tray to clean it. It makes sense that they might divert that water to the drain in that scenario because whatever residual detergent, bleach or additives you have in the tray might be bad for whatever laundry you are currently washing.

Perhaps do your own test to check that claim ... pull your drain hose and aim it into a bucket or other container of large-enough size to see if the STPP power (or use powder detergent if you don't want to waste STPP) immediately runs or is pumped out.

If so, simple matter to sprinkle the STPP atop the load ... assuming 1) that the flush water doesn't shower over the load on the way to draining, and 2a) that the load doesn't tumble first which dump the STPP off of it and possibly into the outer tub where 2b) the flush water may dump it if routed through the tub to the sump for draining away.

dadoes - Thanks for the suggestions. However, if what you say is true, couldn't I just put the STPP in the middle of the items in the laundry (instead of sprinkled on top)? Are you certain it won't cause discoloration or damage to the laundry while it is in direct contact with it?

Also, I should mention that the Miele rep said I could put the STPP in the prewash tray in the W1. However, if I do it this way, I have to select the prewash option (which makes the load take even longer to wash). Also, I'm not sure if that introduces it at the best time in the wash process.

I always put the STPP in with my clothes and have never had anything happen to them. Either sprinkled on top or piled in the middle. And I even do that on a delayed start load where the STPP sits on the clothing most of the night and starts washing early in the morning. Granted, this is jeans, T-shirts, socks, ect. no fancy fabrics.

What the rep said might be true. The detergent dispenser on the W1 doesn't always take water through the detergent cups. If you don't use TwinDos for the wash it will run water through the detergent cup because that is the only way to get detergent in the wash drum.

For the rinses, the water does not run into the tray except for the final rinse which directs the water through the fabric softener cup. Any other water say for the first and second rinses if you are doing an extra rinse, will run in behind the tray with some of it running down that ramp on the right side.

So if you put detergent in the cup and some of it doesn't get washed out. It won't get flushed into the rinse because the water is skipping the detergent cups entirely, and for the last rinse two 10 second shots of water are taken through the fabric softener tray, with the rest of the water bypassing the cups.

I don't think there is anything wrong with putting the stuff on top of the clothes or sprinkling it around and I have done this. The first thing that happens when the water comes into the drum is that the clothes are turned over so whatever is on top gets

wet immediately.

Kim and Jerrod (et al) - Thanks! Based on what both you and others here have said, I plan to just put it in with the clothes. Kim says she's left it in for a long time on delayed start with no problems. And it occurred to me that, if I am concerned about it being on the clothes, I could put it in one of those small, soft silicone pinch bowls on top of the clothes. That way the STPP would not touch them until the agitation begins and the water is flowing.