Is their a way to set the flags for entei and raikou being seen in crystal?

[Trusty]

I am having the worst time locating them, and all the tutorials online are mids and assume you go from the tin tower directly to routes - which I sadly didnt do - Is their a way to set any flags or change anything so that they show up on my map as if I have seen them already so I can more easily track them? been trying for days, having a bad time lol trying to living dex this, but these archaic mechanics are tough! ty for any direction!