These were found in Milton Berle’s Private Joke File.  He admits that some were “borrowed” from others:

A pig bought on credit is forever grunting

A wet bird never flies

Few people blame themselves until they have exhausted all other possibilities

It’s a bad cook who can’t lick her own fingers

You always get the last word if you argue alone

When we are flat on our backs, there is no way to look but up

Only the wise can be perplexed

A crowd is not company