Rock snot, how to remove it?

[GFrank]

Got some rock snot on my waders and boots, want to make sure it's fully removed as it's technically invasive - apparently even one cell of it can be transferred to other rivers and lakes. What's the most effective way of removing it, advice online about it is different on different sites and the clean drain dry is a bit vague? Also, for future reference, how can it be cleaned from boat, I'd probably need to drain everything and pull the plug if in water?