A Wiggly is a good pristeger vs Nurse?

Wiggly doesn't deal enough damage to kill a high level Blissey. You're better off using Fighting types or other mons with solid attack stats, because not timing out is by far the main priority when prestiging against Blissey.

I think the best option at least for me is never prestige against a Blissey for 1k prestige, if the Blissey is at the bottom and you need a spot, prestige against her with mon around the same cp or a bit lower, like 200-300 lower, but not half their cp, that way you will get more than 500 prestige on her battle and even more on the following mons.

If the Blissey is half way or top of the gym just prestige against the mon before her, leave and repeat the process until you open the spot.

I am almost sure it can be done with some half cp mon but probably you will need 2-3 of them, for me it does not worth the time and resources to prestige against Blissey with mon half of her cp.

You may use several low cp pokemons for prestiging Blissey. If 1vs 1, Machamp is the best prestiger to blissey, recommended CP 2200+, as this ensures it has enough HP and Attacking ability. Others with low cp, like Dragonite, Gyarandos, Tyranitar, Flareon, Ursaring, Hitmonlee, Primeape, Poliwrath can also be considered.

FYI: https://www.youtube.com/watch?v=MNz89FAmju4

Wiggly doesn't hit hard enough even if it won't get knocked out. Same goes for Vaporeon normally.

Since timeout is a real possibility against Blissey, the best prestigers against her are the best counters against her, namely Machamp...After that, it will probably Primeamp, Heracross, Machoke, etc...Ursuring is servicable as is probably Exeggutor w/SoB, etc...

I usually won't bother prestiging against Blissey neither, but if it's not over 20k prestige in the gym, I just use anything less than Blissey for 500+ prestige and do possibly 4 fights (or 8 if 16k prestige), but anything else afterwards is easy with 2000+ CP Pokemon.

2300cp firefang + wild charge arcanine can win 2900cp blissey with pound and psychic.