I also had them for years - well over 10.
Had a big crop and samll crop on the ball of oen foot and a smaller set on the other foot (I think - not sure now about whether they were on both feet).
I can remember my Dad freezing and cutting one out (before the larger crops had developed) when I was in my early teens.
Eventually, at about 30, decided I needed to get rid of them as they had started to srpead to the side of the foot and cause pain. treated them with salicylic acid - dripping the acid on to the centre of each verruca and covering with a plaster. It was agony as I was treating such a large area. At one stage, ti was like a whole thick layer of skin was lifting off the sole of my foot.
Stopped treating them when I was going to be going off skiing, to give my feet a chance to heal. At this tage, they were much reduced - only the Mummy and Daddy verricae were still quite large.
Anyway, after my skiing holiday, I noticed that they were finally disappearing. it was as if I had managed to get rid of enough of them thast my body could then deal with the rest.
And as it was my body that finally got rid of them (rather then me cutting them out), I now have full resistance to them, and have been free for over 15 years!