Which technique - ORS or pulley - do you mean?
ORS - can be done with a curb as well as a snaffle, but pull straight back with your bicep, with your forearm in exact same line/plane as the rein. Train horse priorly, without the curb, to save horse's mouth. A curb multiplies pounds of pressure many X, so you're not going to want to actually pull on the curb, because you want to save his mouth. (unless absolutely necessary, in an emergency)
Pulley can be done with both snaffle & curb, but tact is needed with the curb, for same reason.
Last edited by Northern; 03-25-2011 at 11:10 PM.