Coastie Mike, I would just rinse them and not worry about it. A little organic sea[ should be good for your garden, if you use it before it gets really hot outside. You can also set up a tarp to collect water, by forming a slide with sides, into the tote. one tenth of an Inch of water can supple a full tote. Think bungie cords to hold them in as clean a spot as you can find. You can use skinny trees, away from larger trees full of leaves. If you can't do that, skim with a fishing net.
I use rain barrells coming off the roof. Today, I will cover the downspouts, until the pollen is washed off the roof. For drinking, I would use cheese cloth and put it through my Berkey water filter. Let us know how it goes.