I usually don't swab till 5-6 shots or sometimes ooner if it gets too hard to seat the ball.
This 'necessity' to wipe at any time, shows your patch is too thin, or the ball too small. If it gets the least bit "harder to seat the ball", you are building fouling in the bore - our bores remain consistent from the 1st shot to the last of the day and THAT might be the 20th, 30th, 60th, or the 100th shot. That all depends on the day and how long we shoot.
One fellow we shoot with on Sundays, usually starts shooting the trail at 8AM. We normally arrive at 10AM and shoot until 1:30 or so, then all go for lunch at the Bonvoyage Restaurant. So- this man, also known as 'Hatchet Jack', has been shooting for 2 hours on the trail before we even get there and since he's alone for that length of time, he's usually fired off close to or over 50 shots. After we arrive, a normal day would see him firing off another 50 or 60 - like us, he never has to wipe his bore, whether he's shooting his .50 or .58 rifles, or one of his smoothbores. They do not get harder to load as we've taught all the benefits of a good smooth muzzle crown and tight combinations.
Yes - he uses a short starter & his hand for seating the ball into the muzzle - we all do - no mallets, no hammers are used, just the ones the Lord gave us, our hands. HJ also only uses his rifle's or smoothie's ram rod for loading. This man keeps track and a recording of every shot his guns have fired. He is VERY meticulous that way - details are VERY important to him. Only his new .58 Hawken Full stock has fired less than 10,000 shots. He's at 20,000 on some of his guns. He shoots Sunday and Monday - every week - that's a lot and he's dedicated to this sport. Keeps him out of trouble -
.
A local guy here is kept busy at times, with sometimes lock or spring repairs as well as frizzen re-grinding and/or replacements - they don't last forever, at lest not for much over 10,000 shots each.