What is the most discrete and convenient way of consuming marijuana?

I am going to this camp soon and I know that my friends and I won't be able to go out and smoke so I was wondering what I should do. I have 4 grams and I want to be able to consume it indoors. Smokeless. No vape either, I mean no scent whatsoever. If I make brownies will the thc still be active if I keep them stashed away for a bit? Like a couple days? Or should I make like some tea or something? The only thing I don't know about is if I do make brownies out of it or tea or whatever, will the thc stay active? If so for how long?