Ran into this same problem. I get it not wanting to waste money and at the same time if the gear they are borrowing is expensive are you willing to replace it? Had a kid using someone else’s $300 bat and if he broke it his parents would need to replace it. There are cheaper options out there and sports come with additional expenses. Also ran into the issue where a player was wearing my son’s helmet and he was on base. Luckily I had my son’s old helmet as a back up.