You have an infection, so napisan is not going to help you with that. It will clean crud, but it will not STERILISE.
I would
1: Wash with napisan, ensuring the tap is pulled apart and washed thoroughly.
2: Sterilise with Sodium Hypochlorite, including the still pulled apart tap, o-ring, grommet, airlock. Make sure you take a chux or something to the thread in the fermenter too. Also sterlise anything that touches your brew, spoon etc. (edit - properly diluted to correct proportions, of course)
3: Rinse everything with boiled water until there is no more smell.
4: Sanitise with no rinse sanitiser.
5: Put a brew down with complete confidence, following my normal procedures.
I would
1: Wash with napisan, ensuring the tap is pulled apart and washed thoroughly.
2: Sterilise with Sodium Hypochlorite, including the still pulled apart tap, o-ring, grommet, airlock. Make sure you take a chux or something to the thread in the fermenter too. Also sterlise anything that touches your brew, spoon etc. (edit - properly diluted to correct proportions, of course)
3: Rinse everything with boiled water until there is no more smell.
4: Sanitise with no rinse sanitiser.
5: Put a brew down with complete confidence, following my normal procedures.