Re: wrist straps for pull ups
If it really is only your grip strength that's holding you back from getting the 10 dh pullups, then focus on grip work.
* Hang from the pullup bar, working up to 60s holds.
* Do farmer's walks.
* Deadlift w/o straps and with clean grip (no alternating grip)
* Do more deadhang pullups
Your grip will get stronger, and that will help everything. Don't cheat your grip just to achieve a different goal that's only available with accessories.