Do NOT use locktite under any circumstances on a prop nut.

Wood props compress easily and need re-tightening. I've never had that problem with MAS or APC props. Just don't use a 4-way "cross" wrench. Get yourself an 8 inch long box wrench of the correct size and you will be able to actually get them tight. Don't worry about damaging the crank or the prop nut by over-tightening it, you're NOT strong enough. No, that's not a challenge or an insult.