A piece of heat shrink tube over your 1/4 or 3/8 flex adapter will allow you to snake a socket and bolt in to an impossible to reach area and still maintain the
swivel action.Also just a small piece of paper over the head of the bolt or nut will retain them in the socket.

To remove a real stubborn bolt or nut heat it with a torch and then hold a old candle against it,The melting wax will wick down the threads acting as a lubricant.