This might sound like a stupid question, but do just soap and water wash off pheromones?

It takes lots or scrubbing.
I can sometimes still smell them after 3 showers

Mmm...depends on the molecules. I've found Lava soap works quite well...or a brillo pad Seriously though, Lava soap works quite well, but it's a bit harsh (literally hence the brillo pad comment). It's meant to be used to clean your hands, especially if you're the type to do heavy manual labor. It's a man's soap

Can´t remember right now what was the solution exactly ...

but some guy´s over at PheroTalk found some soap that removes mones quite well !

Pago

I remember a while back Tisha recommended using Witch Hazel on the affected area. Then washing with regular soap and water. I hope this helps.

ODG

I use body scrub. It has manual exfoliators. Works very well. I buy mine from Mara at Love Potions for $7 a pop but admittedly they would be too girly some months (new scent every month). Maybe if she had enough interest she would do a boys' version for you guys. Or you could try a scrub from the grocery store. I prefer Mara's versions because they smell great and most months are gentle enough to use on your face and delicate areas. They have sugar (sometimes salt or coffee grounds) and flavoring oils/fragrance oils and a sudsing soap all in one product.

I used exfoliating, body scrubs, shampoo, rubbing alcohol, washing detergent (powder works best) etc.
It seem to come off, but sometimes comes back though faintly.

A good scrub with a soapy face washer is good enough for me, however some phero users i know use 3% hydrogen peroxide solution to scrub over, although if i wanted to be thorough then urine offers a superb efficiency