they will hold the axle tight if you tighten them down enough, grease and all. Just don't overtighten and break an axle or something. The grease helps when it's time to loosen the nuts.
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1989 Schwinn Paramount OS
1980 Mclean/Silk Hope Sport Touring
1983 Bianchi pista
1976 Fuji Feather track
1979 raleigh track
"I've consulted my sources and I'm pretty sure your derailleur does not exist"