Coating the inside of the foundation will do little to stop the real trouble.
90% of the fix is outside not inside.
Adding a french drain outside with a drain line that runs way away from the house and coating the outside of the foundation with foundation sealer will do wonders.
Is there working gutters with down spouts that lead out way behond the foundation?
Does the grade up againt the foundation sloop away from the house?
Is there mulch or flower beds up againt the foundation?
It's never made since to me to try and drain a foundation from the inside.
Why not prevent it from ever getting in, that way if the pump fails there is no flooding.