well yes and no....if you lay it as thick as is reccommended (3in) you risk ending up with a slimey smelly mess....lay it any thinner and it wont work as a mulch. I mean you can chuck a thin layer on to break down and improve the plot but it won't prevent water loss as a mulch would....maybe mix it with other drier mulch material?
Yes, stuff it into strong plastic bags then tie the bag tightly, pierce several times, store it away and forget about it for a year.
12 months up, you should have a good mulch for the beds.