CBT Mistresses specialize on CBT which is Cock and Ball Torture. Not all Dominatrix’s offer CBT as its a very personal option. There is nothing like submitting and handing over the your cock and balls over to a Mistress to torture and whip at Her will and want.
CBT is one of the ultimate in submission to a superior Dominatrix, you will be at the mercy of the Mistress and will have to use the safe word when the level of cock and call torture (CBT) becomes beyond your pain threshold.
Part of CBT is cock stamping, heel torture, ball squeezing and cock stretching. Some subs love to have their cock humiliated as part of CBT where their pathetically small cock is laughed at my the Mistress.