I don't use blockers, but I expect these are a good choice. I'd think plastic would be preferable to wood since you are blocking a wet or at least damp sock.
For socks I keep, I just use my feet to block them when I wear them. Since socks have negative ease, wearing them spreads out the lace (if the are lacy) so it looks nice.
I do block them if they are gifts, just so they look nice and crisp when first seen. But I use home made blockers from wire coat hangers. Easy to adjust to any size sock.