"She may remove hair from her armpit and from her private parts, either by hand or with an instrument".
Leaving aside who would do it by hand...I suppose this means both practices are hardly new, and both are sanctioned as much as cosmetics are.

HOW do you do it by hand?

I assume a tweezer is considered an extension of hand, similar to a fork is.

huh. Then what would be considered an instrument?

Literally by hand is perfectly possible. Painstaking and tedious, but possible.

shaver

what's the difference?

between a tweezer and shaver?
I consider a tweezer an extension of the hand and a shaver a utensil..What do you mean?

why do you consider them to be different?

A spoon, duh.

Because I think that's how halacha diffrenciates (but could be 1000% wrong) since a fork/spoon is considered an extension of hand, but peeler, egg slicer, potato masher is considered a utensil.

Edward Scissorhands, as I can best recall, was widely regarded to be a validation of this concept in Rabbinic circles when the movie first came out.

There's a difference between a fork and tweezers. Forks aren't there to aid the eating as much as they're there not to get the hands dirty, and thus are an extension of the hands much as gloves would be. TMUAFAIK.

Why wouldn't you just assume the statement is literal? It was quite common for hair removal to have been done by hand in ancient and/or primitive cultures.

OTOH maybe if a knife is not a kli tweezers shouldn't either be. OTOH maybe a knife is not a kli only because of derech achila in which case tweezers would be a kli.