another pokemon heart gold question

[Mimispider]

so i had this question about the elite four and i have huge trouble leveling up my pokemon. is there ANY way i can get inside Mt. silvr in heart gold without beating the elite four? if not plz tell me a way to level up my pokemon faster. also if you know, could you tell me around how much time it takes to level up my pokemon to lvl 48?

[Inari]

Mt Silver is only accessible after you have all 16 badges.

[Mimispider]

oh ok. what is a super fast method to lvl up my mons?

[Inari]

There is none really. Just fight the Golbats and Donphans? Idk what the exclusive is in HG cause I have Ursarings in SS and they give amazing exp

[Mimispider]

oh ok. i will try that