i tend to wash about 2 or so days after relaxing; i get paranoid that the stylist might not have washed out all traces of the relaxer.
after my last relaxer, washed with ORS aloe shampoo, used porosity control and did an aphogee treatment as well.
i figure it doesn't really matter how many days after i relax, it doesn't revert 'cos it's a permanent chemical process, so why not? but that's just me.