I use a Canadian product called Dizolve -- I think it is available on Amazon as well. it comes in a fragrance free version (which I like). One strip is for a typical load in a machine, so I use about 1/4 - 1/3 strip in my when doing hotel room laundry (the "Scrubba" is like a big rollup dry bag )

It also comes in handy if you do come across a self service laundry ("Laundromat") and you don't want to use powder from their vending machines (fragrance, too expensive, etc.)

I bought for travel but now use it a home as well instead of those big plastic jugs of laundry soap from Costco (or where ever).