Yes, but how much do we use for what purpose? Do you mean putting the MDMA in a water bottle and slowly drinking it to get the doses?
I would recommend you stay away from that. MDMA is best dosed at once, if you take too little at first it is hard to take more and get the effects you were trying to get in the first place... redosing seems to just lengthen the high, not make it more intense. Since MDMA dosing is rather tricky to find the "sweet spot", I would recommend you just weigh out proper doses and place them in capsules.
I take ~150mg in a cap as my first dose, followed by 100mg as a redose. I find any further dosing is unnecessary and leads to a much worse comedown in the end, as well as being quite inefficient..