Hi, when I started two years ago (again) to process my own B&W I adopted the Ilford method - slightly amended (always use fresh water):(posted 8891 days ago)1st wash: 10 times inversion 2nd wash: 20 times 3rd wash: 30 times
Just a bit extra time - I'm still working with those negs and can't see any problems.
Of course, can't predict what they'll look in 20-30 years from now. But consider: most negs from 50 years ago were not "archivally" washed and look at them now - most of them pristine as ever .....
Good Luck!