I have some of the woolen balls, and must say first I haven't tried them for sheets. If your load included fitted, I'm imagining them just adding to 'the ball' and inserting themselves into those fitted corners at their first opportunity. We have a feather bed topper. Love it, but my wash just for our bed has become flat sheet and 6 pillow cases = one load. Second load (just for remaking that one bed) is two fitted sheets - one for the mattress and one for the feather topper plus a protector for the topper. I have to stop the dryer about 2/3s the way through the dry time and unwrap the two fitted and protector every.single.load....no way around it. All would fit easily into one load of wash and dry if they would just play nice together.

The dryer balls do NOT keep your sheets from forming into a ball. When I wash our king sheets - one flat, one fitted and two pillow cases - I stop the dryer a couple of times to shake everything out and start over. I still use the dryer balls with lavender essential oil on them when I dry sheets, as I don’t use any other forms of softener.

Just used them (wool) for the first time. I dried a full size cotton quilt and sherpa lap blanket. Neither blanket normally twists in the dryer but I did notice the quilt didn't "fold" like it usually does in the dryer. I watched them tumble for a few minutes and the balls did seem to keep things fluffy and separated. These were dog blankets.

The noise issue was a total non issue. I used 6 wool dryer balls and the noise was barely noticeable. Doubt anyone would be aware of it if they weren't listening for it.

I bought some lavender oil today. How much should I apply to each dryer ball?

I’ve used 6 balls for every load, including sheets for a few years now. Haven’t noticed more or less sheet balling than when I didn’t use them. Have noticed the shorter time it takes to dry. I add 5 drops to 2 or 3 balls for all of my laundry, 3 loads usually, meaning I add once then not again until the next time I do laundry