The advantage in esters are their greater solubility in oil over the free alcohols. I agree, if it's a base steroid its best suspended in H2O (with very little or no BA) but esters are generally in oil. Chorbutanol is a better choice here than BA. BA makes test suspension turn to mush. Unless the crystals were very, very fine (1-5microns) and a low ester like acetate or prop was used, I'd just put it in oil. An oil like castor with a co-solvent like ethyl oleate to thin it would slow it down about as much as you could ask for from an acetate. Maybe 2 times per/wk injects, but I am unsure of the partition coefficient with TA so don't quote me on that. It would take some experimenting to see.