N.B.
With my daycare children (who potty train right at 24-28 months here with a "3 day method" as a base with parents at home..which is more like a5 days or so with full support and follow up from me and NO dependence on diapers of pull ups during their time at my house once its begun)...I do ONE M&M at the beginning for either deed...not for trying, but for producing something in the toilet.
After they really got it down (#1 is always first and quick in those first few days..I have never NOT had a successful child in the last few years of doing this method)...I just sorta of distract and rush them thru the hand washing and silliness to get them to forget about the candy...and if asked I say, lets just do that for #2..and mostly they just give me a look and we move on.
Then we do them for #2, which is less frequent, so the cany is not so "in their face". Once they have the pooping figured out, I start saying "oh, I forgot to buy them" and similar excuses. I never leave them on the counter in their little container or where they are always in sight or where they can be reached.
It just always works and is easy to wean off them. Distraction works great...shuffling them out of the bathroom once the deed is done...make hand washing silly and fun so they forget and just being a "spacey daycare lady (Mom for you)"
With all your steps, maybe pick one to get rid of first...stickers or candy...and go from there. Withing 2 weeks you can have them all gone.
Good luck!