Best use I've found for empty model glue bottles is to refill them
I bought a 100 ml bottle of acetone and another 100 ml bottle of butyl acetate some years ago, and every time my Tamiya extra thin bottle is empty enough that the brush won't reach the glue without screwing the cap on, I put about 10 ml of each in using a laboratory pipette, close the bottle and shake it for a bit. This is not only much cheaper (those two bottles together cost me about the same as one bottle of TET, but I've got five times as much glue for the money) but prevents clutter or waste from empty bottles.
TET is not my main glue, though — I mostly use a solvent mixture I buy in hardware stores, for about €8 for 250 ml (for comparison: model glue costs about that for 40 ml around here), and that I use to refill a Mr. Hobby glue bottle.
I only buy a new bottle of glue when the brush wears out