The last time I did it the plant looked like a bansai tree, it was extremely bushy but the leaves were only tiny and weird looking, all mutated and shit. I don't think it's worth doing (unless it's your only possible source of new clones or something), you could have new cuttings rooted and growing by the time a flowered plant has reverted back to vegetative growth. Plus the soil will be depleted of nutrients and it will be root-bound and have lots of dead roots. It's best to start over fresh if you can.