I have suffered from this and would advise trying a Powerball - it's a gyroscopic exercise device and whilst taking a bit of getting used to is amazing.
Agree - Give the caliper assembly a good clean first and then with care, remove each piston and give them a thorough clean with brake cleaner.Then ideally using the same brake fluid as in the rest of the system - work a little fluid into the seal and reinstall each piston.Give the caliper a good clean up afterwards.
This information is really useful to riders new to trials such as myself.Presumably any tools and spares that are carried to in a well padded bum bag ?.
Does anyone carry a spare clutch lever or is that a bit OTT ?