I used Sudocrem for about 1 week, about 20 months ago and I’m still clean since that moment. I’m not sure anymore whether I also used it at night, but I had it on my face during the day (while working at home) and washed it off my face every day.
So in my case, 1 week worked effectively, but maybe using it just a few days could also have worked. You could try putting it on the face after work, maybe leaving it on the face during the night. (Although maybe that could cause a sticky mess on the pillow and hairs.)
@col, if you want to try Sudocrem, then I would do so when you still have some Soolantra left, just in case things go bad by using Sudocrem. (In my case, Sudocrem did cause some irritated feeling and redness on the skin after using it for some days and it did cause clocked pores acne. Both were temporary.)