Agreed: when I was on the road internationally for 3 months, I always used the hotel laundry service if they offered one. Though if I'd known there were places like Freddy Leck (laundromat in Berlin with free wifi & serves coffee & cakes) I would've used that instead. Don't be a smelly traveller.

If you're prepared to take checked luggage, you can take a lot more clothes with you (or have room to buy more on your travels). Jeans were fine for me in Europe & even Vegas in July, though I'm used to 100F heat in summer.