Question: Grafting 2 into 1

Doing a little R&D - I have two female plants, nicely established, same age, stems very close together.

Can I, and how would I, graft the main trunk stems together to splice her into one plant?

I know I'd have to tie them up, & I've already started training her that way.

I have heard of a plant being grafted to anothers root ball, but the stem pretty much lined up so that fluid and nutrients flowed properly from roots to plant, i don't know about one to another like you asked but if you post some pics it would be easier to help.