In written descriptions it is noted as water, so it should be possible. Do try to keep the corrosive moss out of the fuel scoops, though.
That answer is specific to Sturgeon's Law. Other worlds and other liquids could be different. Though, for instance you can get hydrogen out of acids like hydrochloric acid and sulphuric acid, but there would perhaps be issues with the refining process... it may cause some unintended consequences like completely corroding away scoops and refiners. With "real' chemistry, you'd probably need different and specialised equipment for each unique liquid.
I would suppose if the corrosion is above and beyond that normally encountered.
It could be two pretreatments, one neutralizing the corrosive component, and the second filtering out the solids, before letting the fluid into the scoops, so you may need to land and set up the equipment externally; or, may be set it up in the cargo hold, and divert it there first.