I don't have any direct experience with that type of clen but here are a couple suggestions.
1) find some way to dilute the solution and with enough mixing still keep a consistant concentration. Then you could get it down to perhaps 500 or 250mcg/ml.
2) you could do the math and use an insulin pin to measure out a tiny amount and squirt it in your mouth.
Only suggestions, like I said I have no direct experience with this type of clen but I came across the same problem dealing with peptide protocols.