ANSWER:

The prohibition is in going to the masjid and praying while you are smelling of garlic and onions. If you manage to lose that foul smell, you can go to the masjid.

With regards to onions, if we have dish/meal that’s has onions raw or cooked, can we brush our teeth with minty toothpaste/drink mouthwash and go to the mosque to pray and if not how long in hours do we have to wait before we can go to the mosque after having onions