Water pump with aspirator much cheaper then vacuum air pump.
It was used for clandestine manufactures in old times. Cold water makes strongest vacuum, i dont know why.
All types water pump Will work. Submersion type unlikeble becose of Hot. Also if somebody wanna use fresh material for extract, need extra step redistill all the time. Or maybe add extra part - distill column, this choice May save more time with 96+% purity.