I don't know, piling sand on an SLE or a bow seems to be a shitty way to try to launch it. I did several self launches using sand on the wingtip with my 9M Waroo when I had it. Sketchy. Try the chicken loop/PVC method.

Unless you are doing a big downwind session with several stops and starts, as alluded to by Tom, using PVC is not a difficult or expensive method. $5.00 for a piece of PVC, a $10 mallet, and that's it. Tom, I'll show you this the next time we are at the Skyway. It's easy as hell. You will ultimately love it, especially for that night riding you do, because it allows you to check your lines before committing to the launch.

Also, I have doubts about making the anchor too strong (like the metal corkscrew, etc., boat anchor from a container ship, rebar, whatever). First, I don't want to break my toes on a hard-to-see corkscrew or piece of rebar that someone has pounded into the beach. Also, one of those lying around could easily tear a kite. Most importantly, if I somehow f*ck up during a self launch and the kite powers up and starts raging through the window while I am trying to self launch, I do not want the PVC to hold the kite, I want it to release and let the kite go. Otherwise, the kite is going to loop and ultimately smash into the beach, dirt, whatever and explode.