No, dont try it. It doesnt work. It might in very rare case but all it would be good for, is a display.
The only external GPU dock that would give good performance are the ones that are based on thunderbolt or MXM port.
I've already fried by Motherboard (GA 78LMT USB 3 rev 6.0)It would work but would give you 30-40 percent, maybe less of the performance of a gpu. Plus, if there is a quality control issue, it can fry your GPU and your pc.
Bigger and better companies have fried components because they screwed around with PCIE slots ( I'm looking at you, NZXT). So I'd say don't try it. It's not worth it.