You shouldn't need to use an antifog agent. All modern commercial developers have been formulated to give minimal fog consistent with their recommended film speed range. For instance; D-76 is inherently very clean working, and has a solvent action that an antifog agent would interfere with. Acutance developers will lose some of their sharpness if used with an anti-foggant too.(posted 8161 days ago)
It's also not widely known that many modern films themselves already incorporate anti-fogging agents in the emulsion.An anti-foggant might be useful for outdated film, or film that's been badly stored, or for stale printing paper, but it shouldn't be used indiscriminately, or as a matter of course. You'll just lose film speed for no reason otherwise.