I think the myth/misinformation is that the loss of sensitivity is permanent. You can certainly overdo it with some toys, and leave yourself both sore or numb (or bored), but if you abstain for a short time (or change stimulation type or area) then the sensitivity returns. 
Mrs Chimp is a fan of the suction-style toys, and is very glad she discovered them. 
However… I’ll throw in the universal caveat that every body is different, so everyone can’t like everything equally. One person’s guaranteed orgasm machine could be the next person’s ‘meh’, so there isn’t a universal ‘definite’ that will suit everyone. The suction toys are very popular, but there are some who don’t get on with them.
But if anyone is on the fence, don’t forget about the new 100 Day Money Back Promise