Where did you get this information? I am an electrologist. Disposable probes are used because we do not want to transmit any type of infection or bacteria to anyone else. Check with your state laws but most have to use diposable probes. Also, your electrologist will decide wheather you use an insulated probe or not I suppose you could recommend it??? The reason an insulated probe would be used is: If an area that is being treated has alot of moisture you could get surface blanching. The current is delivered at the bottom of the probe and with an insulted probe the shaft is covered so that the current is directed more to the bottom of the follicle and less is traveled up to the surface. And YES Insulated probes ARE DISPOSABLE!!
Also check out on Andreas web site about finding an electrologist she has some really good pointers there. Look for C.P.E. Associations they belong to, If their registered, Ask for references, Good Luck.