Some of the saints, especially some of the older ones, were indeed merciless with their flesh. I cannot really comment on that except to say that I won’t go there with penance myself. Indeed, St. Therese of Lisieux, now a doctor of the Church, didn’t go there either. She instead practiced the mortification of performing her daily tasks to perfection.
How horrible would that be? Doing what’s required of me? The dishes? The laundry? Paying bills? Planning lessons? Keeping my desks cleared? Weeding the yard? Honestly, if I ever master performing my daily duties for the love and service of Christ, I may have to start considering some additional mortifications…
OK, as to penances to deal with temptations, especially of the physical kind, prayer is the first and best place to start. But you can’t wait until temptation arrives to start praying. I speak as someone who struggles desperately with these temptations. A few months ago I began attending Eucharistic Adoration regularly (a few hours a week) and having a “no excuse” policy about going to daily mass on the two days a week my schedule allowed it.
From there I noticed an increased desire to read books by the Saints. I began with
The Story of a Soul by St. Therese (my patron) and then moved on to St. Josemaria Escriva’s
Furrow and a book recommended by a friend (author and title completely forgotten at this moment).
So I was going to Adoration and daily mass regularly and reading some pretty awesome material – and then I had a major (and disgusting) accident at home with one of my power tools on Palm Sunday. As I was lying there alone in the ER, with a bloody bandage on what used to be my perfect hand, all the things I had been reading flooded my mind. Images of Our Lord on the crucifix and truly present in our beautiful adoration chapel filled my imagining. And as I waited, I felt both terrified and yet at peace, offering my sufferings as the music from Good Friday and Easter Vigil played in my head (I’d been practicing the music on the piano that very morning).
You see, prayer, adoration, and excellent spiritual reading aren’t just good for resisting temptation – they’re GREAT for building virtues and a truly useful store of strength in all situations. These graces have now led to my immediately changing the channel even when I see something as “innocent” as a passionate kiss on a TV program or commercial. I just won’t let these things into my mind now – I can’t handle it, I admit it and go joyfully on my way

It is a process to overcome these temptations, but God is on your side. He wants you to succeed – and grace will build upon grace built upon grace. We’re talking exponential growth. You can’t do it, but He can
My hand’s doing better, by the way, and I’m already learning (slowly!) how type and play the piano with nine fingers
God bless you – and don’t give up the fight. “Never give up! Never surrender!”
Gertie