Grafting.... Want to Graft a Chilli plant onto Tomato Root Stock

Anyone tried grafting a different plant onto another rootstock?

I saw in B&Q this year that they were selling Aubergines Grafted onto Tomato rootstocks and with a larger yield (guessing that Tomato roots collect more nutrients etc than Aubergines), so though I would try this with Chillis to create a higher yield.