I can't see where my way would be any less safe than using a dowel. I have far better control of the pistol since I have both hands wrapped around the pistol instead of one. The pressure I apply is inline instead of offset so I don't have the possibility of pushing the gun sideways.
When I am applying pressure I have the barrel pointed down at the ground within a couple feet of the ground.
This is the way I watched my father doing it when I was a kid. He grew up shooting a cap and ball pistol. He was born in 1888. I never saw him have an unintentional fire and I've never had one myself either in 60 years. Caps go off from impact, not pressure.
Of course, I grew up and learned most of the things I know how to do before everyone was in such a panic about safety. When I was a 6-10 years old my dad would have me light the fuses on dynamite charges for him. He was a care taker at a cemetery in Oklahoma. When you dig a grave there, it's about a foot of dirt covering solid rock. Each grave had to be blasted out. ( My mother would have killed him if she had ever found out. lol!). I learned to set shaped charges at 6 years old.
I don't think anything about doing things like making my own gunpowder,( Oh my god I'm gonna blow myself up!), casting lead balls, ( Oh dear! I'm gonna poison myself.), drive without wearing my seat belt, and ride a motorcycle without a helmet. i drink moonshine when I can get it, an have been smoking for 50 years and can still out breath hold free dive longer than just about anyone I've ever run into. I put most 20 year old non-smokers to shame.