Throw all their samples back outside, then very carefully sweep the inside of the LEM and throw the broom & dustpan out too?

In theory, they could have been equipped to partially pressurize the cabin with (say) helium - which would allow some sort of vacuum cleaner to work. But that could have added a fair bit of mass (by the LEM's very tight mass budget standards).

Empty out a glass of water and blow the floating blobs towards the fire.