An indoor kitty got out and now pitiful meows to go out. Should he be let out

[snagglepuss]

on a leash?

My mom's 1 year old kitty was out for 3 hours the other day before we found him. Now he scratchs at the door while letting out the most pitiful meows wanting to go back outside. Mishka has no problems wearing a harness so my mom is thinking of taking him outside with a leash in the back yard. My sister thinks it is a very bad idea as Mishka might get fleas or some other condition. Given that Mishka sleeps with my elderly mom and sits on the table while my mom eats, my sister's concern may not be unfounded. How liable is it for Mishka to get fleas or other parasites from being in a garden? I've seen wipes for kitty paws. I'm wondering if they're safe and effective for killing germs and if anyone uses them.

I've read online some people who have regretted taking a kitty out on a leash because the kitty wants out all the time, others seem to have no problem. Hard to know what to do:(