Hal, spoileron is the name given to using upwards reflex of the ailerons. Because of the direction travel it's the opposite of flaperons. While flaperons have been used occasionally in full size stuff I believe spoilerons are unique to model aviation and that may explain why you have not seen the term before.

Vasek, the idea is that the use of spoilerons induces a negative camber. It's sort of like flying with a ClarkY or other higher cambered section upside down. To fight the loss of lift of the airfoil section thus created you need to rotate the nose up further. To achieve the lift needed you need a very large angle of attack and that suddenly presents the belly of the fuselage more to the air as well as the wing itself creating more drag due to it's suddenly "dirty" airfoil.

But I feel that this is a technique best used on lighter models. I suspect the landing SPEED may even be a bit higher because of the bad lifting and possible stalling charactaristics. But the ability to slow down should be greatly enhanced so you can set up a very predictable glide slope.

Your best bet would be to post the question about using spoilerons in the Jet forum if you have not done that already. This is one of those questions where the real world experience and parameters counts for more than theory. Find out who is using what and what the model wing loading parameters are. Chances are there's a link between those two, and maybe another factor that will guide you with other's success.