hi
i've done indirect & direct high frequency talc is usually used as thats what i used in college but an oxygenating cream is just basically to purify the skin ,increase cellular renewal in the epidermis and dermal layers ,mature dry dehydarated skins supposed to benefit from these creams and is left on for 24 hours to penetrate the skin it is also to make the skin brighter and supposed to balance the ph of the skin .high frequency is good for oily skins as it dries out the sebum and lift it a bit to spark on a spot to dry it out(not too much thou as it causes tissue destruction) and on dry mature skins it is good to increase sebum tot he surface to lubricate the skin and so on... hope this is of some help.
jane x
L2 & L3 VTCT Beauty & Holistic Therapist