Kind of going back to the original question...if you've got a bermed turn and you are having problems with the front wheel sliding out, is is most likely becuase you are not really using the berm, but rather trying to turn just inside the berm.
A hard thing for many of us to learn is to actually trustthe berm and use it. If you put the bike into a berm, lay it over, and get on the gas, it will hold more than most of us initially believe. If you fail to do any of the three, something will probably go wrong.
If you lay it over and get on the gas without actually putting the bike into the berm, it will slide out.
If you put it in the berm and lay it over but don't get on the gas hard enough, the front wheel will climb out the inside and you might fall over.
If you put it in the berm and get on the gas without leaning it over far enough, you will likely go out over the berm.
To actually address your question, if you're in a right turn and the front starts to slide, my first inclination is to stand the bike up more so that the front tire will bite. If my inside leg is out, the bike starting to slide will usually result in the inside foot hitting the ground and helping to get the bike more upright. Also,while doing so I'll likely panic and let off the gas which whill transfer some weight to the front which will also help the front tire bite more.
If the back end starts sliding out, my approach is very similar. Many times the back end will slide out because the rear tire has lost traction due to spinning. Merely letting off the gas will sometimes let it slow down to where it will hook up again.
Please remember that these are the suggestions of a mid-pack +35 rider...not an expert. I'm only here as a moderator to keep MRRMX in check, not to give meaningful advice :). Once Wardy (or Ol89'er or someone else qualified) gets a chance to verify what I suggested, then I'd consider it useful.
Gomer sounds right--
if you are washing the front end out into a bermed corner ..most likely you dint hit the berm.
you turned inside it and the front end has nothng to grab.
but its hard to tell from what youve decscribed so far.
I can tell you that using your front brake while layed over will indeed wash the front end out.
Some riders actually use this technique going into a rutted or bermed corner..if the front end is inside the berm they will intentionally brake to wash the front out into the berm..you have to be off the brake and on the gas at the moment the front catches the berm though !!
so its an advanced technique.
My Gary Semics book suggests that you feather the front brake in a corner with a berm until you are ready to accelerate hard and then you let off the front brake. This helps to slow the bike the bike down, shorten the steering angle and keep weight on the front for traction. I have tried it and have good success with this technique, as long as you feather the front brake and not grab too much.
You have got to have your berm technique down before trying any fancy brake-feathering.
I think Gomer gave some solid advice, and to the original question: You will not brake-slide to a garden-variety bermed turn. If the berm has a rut that has a kink in the beginning, or the turn is pretty tight, then a brake-slide can help you. Most often it just eats away your momentum, offering little advantage.