Bummer you have to resort to the hormones. I have had many successes with both aspirin and light poisoning. Difficult to believe that the combination had no effect.

Mega Gro growth stimulator is one I used many years ago. Inconsistent results, but I was a little wary of even using it, and went with lower doses which resulted in slower results. When I tried upping the ratios, I burned the branches. (use care)
There's a Dutch product or two available also, but I've never used 'em.