The technique of using a string of pearls when you masturbate really does work. It's even better if you use two strings at once. I like to get myself going with fingers first, then slowly insert both strings into my vagina so that one string lies just against the left side of my clit, the other string lies just against the right side. Then I bring myself really close to the edge with my fingers. As I just slip over the edge and lose control to the orgasm, I pull out both strings with one hand (usually my right) and rapidly do my clit with fingers of the other hand. Sometimes I can even have a gigantic cum just by pulling out the strings, no other clit stimulation at all.
This takes a little practice to do perfectly. I like medium sized 'pearls' or beads, the inexpensive ones bought at K-Mart or similar places. Some people might like smaller ones, or larger ones. If you get yourself going pretty good with your hand first, you can get much more of the strings inside, maybe all of both strings, and prolong that wonderful agonizing orgasm. It is a real treat!!!