u/Forsaken_Animal_5433

Hey yall!
I’ve had these silicone bongs for a few years now
I use Kirby (we nicknamed the Kirbong) frequently, pikachu I have trouble with because of the location of the bowl, and getting the heat/lighter flame on it

My man question is..how the hell do I clean them properly? The colour on Kirby has been darkening but I’d love to clean them properly.
I have used orange cleaner on Kirby, and isopropyl alcohol but it just never feels super clean.
Is there a better way to clean it and/or get the colour back?
Eventually I’d like to retire them and have them strictly for decorative purposes

Thanks!