I wouldn't ask to hit someone's clubs unless they were close friends to start out with.
I have had someone insist that I try his hybrid. ("Here, try this - it's the perfect club for the shot you have...") I refused three times, but accepted on the fourth -- after I'd hit the ball with my club (badly sliced). Dropped a ball down, and hit it. It still felt awkward to me precisely because I am the 'idiot' that just might put a sky-mark on a club or do something else stupid --- I didn't want to risk it.
This reminds me of my uncle's favorite golf joke though.
A guy, let's say he's a friend of ours, is walking up to his ball after a nice tee shot, and he sees another golfer on the adjacent fairway hit a lousy shot. The other guy slams his club into the ground, swears, drops another ball and swings again. Hit fat, the ball plops into the nearby water hazard. The golfer, obviously upset, throws his club into the water, looks up, and notices our friend as he's getting to his ball.
"Hey," says the angry golfer. "Do you have a 5-iron I can borrow? I just lost mine."
"Sure. Try it out - maybe you'll have more luck," says our buddy.
The angry golfer takes the 5-iron, drops a ball, swings, and sends another ball to the water. The golfer is outraged, and he grabs the 5-iron with both hands and snaps the shaft in half across his knee.
"Hey! What the hell are you doing!?" exclaims our friend.
The angry golfer stares at him, allows for a brief pause, and says, "If you can't afford it, what the hell are you playing this game for?"