LOL, no, you won't get crucified, not by me anyways. I don't know the specifics of what hazards fabric softener may have on vegetation but it's probably not good. If you could hook up your roof gutter/s to the same water collection system the rain water may aid in diluting the gray water so that all contaminates will be lowered somewhat. vgkg

i wouldnt use fabric softener. and make sure you use mild or biodegradable laundry soaps also. stay away from artificial dyes and fragrances. i think if you use mild soap and maybe add a splash of vinegar to your wash water, you may find you dont "really" need fabric softener. its not uncommon for people to recycle grey water and i think its a great idea.

have you tried this experiment, take a bath towel that has been laundered with fabric softener and one without fabric softener. dry something with each towel and observe which towel is more absorbent? see if there is a noticeable difference.

Here is a link that might be useful: one of many greywater websites