I want something that sticks so they don’t want to wear that outfit anymore… any other ideas non-violent ideas to make them feel unwelcome??

I’ve got just the thing for you. Vegan milkshakes. Well, any milkshake will do, because the point of throwing a shake is to get them soaked in a liquid that will smell awful if it bakes in the sun. It might stain clothes, and it will certainly be uncomfortable. You should probably use a chocolate shake with the klansmen, it’ll stain their bedsheets real good.

The best part about it is the physical harm inflicted is minimal, while the social harm, humiliation, is pretty significant. This is important because humiliation is the achilles heel of fascists, since their world view is based on imagery, and this action disrupts it.

The other good thing this does is it can be used to make a potential agitator leave so they can clean up.

This, unfortunately, is assault (or some other illegal activity), so keep that in mind.