I have dark underarms and I've already used various products to try and make it lighter, but they all didn't work. I was wondering if anybody's done something and has already worked?

The things I've done that didn't work are:

IPL treatment, 10 sessions (costed me a lot and it didn't bloody work)
Papaya whitening soap (different brands like Likas, Sutla, etc)
Other whitening soaps (Yoko, Ponds, etc)
Whitening lotions (eg, Skinwhite)
Vinegar
Lemon


It seems like I've already tried every bloody thing. Can somebody suggest a tried and verified way of lightening underarms please?

Thanks!