1 is too many. I've made it a rule never to dry fire any of my springers.Same goes for NP piston guns.
i am not trying to be contentious but i just go this off of Pyramid:Spring-piston guns: Beeman recommends using two pellets in low-powered spring guns and at least three in moderate- to high-powered air rifles. These are loaded at once to help increase air resistance and stop the piston from slamming into the end of the compression chamber... https://www.pyramydair.com/blog/2009/06/beeman-quick-cleaning-pellets/ Yep i know that beeman has a pony in the race...i do not disagree with anyone would not intentionally dry fire just wondering how serious it is or has it risen to the ranks of Urban Legend.
for a springer or np i would definitely recommend the crown saver and dry patches. its a better option. save the cleaning pellets for the pcp/co2/pneumatic guns that you have or will own in the future.