At the facility we are currently playing at, when your team enters the gates, they give you three game balls. You only use them when you are on defense. Your team has to chase down any foul balls and get a new one to the pitcher. Umpires do not touch them. Opponent does not touch them.
The other org we have been playing at does not do this. They want you to sanitize the balls as they cycle through the dugout, though I have not seen this done much at all.
IMHO, the risk of Covid is much more in breath/coughs/yelling than on surfaces. I'll all for each defensive team using their own balls, but wiping down balls seems overkill with what we know now.