yeah I've done that before. It's exactly like softer dash dancing but since you're only in walking speed you get to move with it and I can do it with out the C-stick stuff he said. That is exactly the properties behind the reverse crawl dashing I need to freaking post a video of. And through a PM I told East the commands and how to do the Boost Grab so I can post that here.
Run(dash) + grab = normal slide grab
Run(dash) + Down-C stick (dash attack) + grab = Boost Grab
note: You shouldn't actually do the dash attack since grab cancels it
Run(dash) + pivot + grab = Reverse/Pivot grab
Run(dash) + Down-C stick (dash attack) + pivot + grab = Reverse Boost grab
the way I practiced this and to show you if you're doing it correctly since it is a subtle difference in distance gain is to practice with the Pivot Grab first. e.g. I did this with Sheik on Falco, on Smashville and Final destination. If you do the normal pivot grab at Falco you should end up failing to get behind them (there are exceptions) and with your back against him, you just end up pushing him slightly.
Now do the Boost reverse grab, what should happen is you end up sliding/swinging past him. If you get the grab to connect you also still slide for a bit with him in your grasp. That is the boost. Once you've mastered that command, do it with the normal forward approach and you will start to see the difference in distance gained from your boosting. It's good to maintain chain grabs going at further distance, and the boost slide from pivot grab helps if you want to gain control of getting them to the edge.