Forget about soaking boots. She is Not ready for that.  Get a few tubs of ToMorrow.  Easy to use.  It has a tip applicator.  Try to clean first, go to another hoof.  Do the Round the world. Then on the second go around, put the applicator in the crack and give a small squeeze.  ToMorrow really works!  If you can do this daily for a week, you will see a healthier frog.

Waterhole rituals are just games you can play with her.  Take a chair and Sit in her paddock/pasture.  wait for her to come to you.  If she touches you, then you can touch her back.  Scratch, use a groom brush but you must stay in the chair.

Another is approach her, get close and offer the back of your had to her nose.  Wait for her to touch you.  Then find a scratch spot.  Get her happy then walk away.  You can do this over a few days or in one day. After you walk 10-15 feet away turn and look at her.  Ask her to come to you.  If she moves a few feet, you can take a few feet to her.  The idea is to get her to see you as a safe/happy place to be.

There are many more. Look up Water hole rituals