Yes, first Betadine and then a numbing cream. You can also wash off the numbing cream with tap water (and a cotton pad). I will change it in our instructions.
I paste here what I wrote in another thread. Perhaps it is interesting for you:
Disinfecting the dermaneedling instrument after dermarolling is more 
important than disinfecting the skin before dermarolling. Of prime 
importance is to clean the instrument after dermaneedling with dishwashing 
detergent and warm water (not boiling water) and rinsing it under a strong 
stream of water to remove blood and skin detrius from the needles. Then soak 
it in Chloramine-T or Ethanol.  This prevents the formation of potentially 
harmful bacteria while the instrument is not used. The bacteria on your skin 
are much less dangerous that what can form when you don't clean a 
dermaneedling instrument.
Basically, if you do not clean a dermaroller, what forms on the roller head 
and needles are the same bacteria as that in a rotting corpse. Whereas the 
bacteria on the skin are totally different bacteria, it's more of a stabile 
ecosystem of probiotic bacteria, a protective layer of beneficial bacteria 
on your skin, a great majority of beneficial bacteria that prevent bad 
bacteria and harmful fungi from getting a foothold.
Your immune system has plenty of antibodies against the bacteria on your 
skin, aquired whenever you cut or chafed yourself.  The same goes for active 
acne. Every time you squeeze a pimple, some bacteria enter your bloodstream 
and you make antibodies against them. Therefore, even if you "roll in" a lot 
of bacteria from your skin, there is only a very tiny chance that an 
infection can result.
So the main thing is to clean your roller after use with water and 
dishwashing liquid, to get rid of the "big chunks" (only visible under a 
microscope though) of skin detrius and body oils. That would in principle 
already be sufficient, but just to be totally on the safe side we also 
disinfect the roller in Ethanol. If you want to be absolutely sure that your 
roller is totally sterile like an operating scalpel straight from its 
packaging in a hospital, then instead of Ethanol, use our Chloramine-T. 
Chloramine-T kills bacteria like antibiotics do. Chloramine-T has in fact a 
double antibiotic mechanism of action. And it is cheaper than alcohol as 
well - from us at least.
Finally, I want to say that we had tens of thousands of customers over the 
past years and that we never heard of anyone getting an infection - ever. 
And that's because of what I already explained: "Rolling in" the bacteria on 
your own skin is in fact quite safe. And simply cleaning the roller well 
with water and a soapy substance is also sufficient, in practice. That means 
that disinfecting the skin and roller is actually overkill, and hence nobody 
ever reported an infection.
Anyone who still is worried about infections should soak the instrument 
overnight in a Chloramine-T solution and the result is total sterilization.