I made a rice bucket while I was out of action for several months at the start of the year (injured foot), and it's a great tool. I found it particularly good as a hand warm-up before I did anything super-intense like fingerboarding.

niaqaeli, this might be good for conditioning and for balancing out the muscular stresses of massage work.

Other minimal equipment stuff: do you have any small hand weights, or food cans? They're ideal for wrist curls and reverse wrist curls.