I too have contamination and it was hard to save them even after rinsing with weak bleach and another rinse in distilled water. I potted them in moist sphagnum moss but they didnt survive maybe due to contamination. Another issue of replating was exudation and newbie like me at first i mistook as contamination. I read rinsing in distilled water and introduce into new jar to solve the problem.

Hope you are successful with those tiny protocorms.