Well never tried x) sounds funny and I do not see why it should not work ...
If the pH is at ~ 3 or lower and you stirr it strongly (!) that would be ok if given like some weeks.
Still it would be hard to get the dosage, I mean you would normally say 1 % per MHRB, but as you will not refresh the water it may be less than this and stop at a certain number below.
And I dont know about any contraindications, there is always told to avoid that Tyramine-Food, but this is not Tyramine stuff and ALSO it is a common misbelieve or let's say it is overdone, as that Tyramine-diet is only needed for the medical MAOI (Phenelzin mostly), while the Harmalas wont cause a Serotonin-Syndrom upon ingesting Tyramine (it is still metabolized by that other MAO enzyme, that Harmalas dont inhibit, in contrast to Phenelzin).