What is the best method for joining cotton/bamboo yarn?

I’m crocheting a vest with a cotton/bamboo viscose blend (52%/48%). When attaching a new skein I tried to use the russian join, but it came undone because the yarn unravels itself quite easily. It’s obviously too slippery/has no grip. What method would be better? Just a knot doesn’t seem like a good idea. Maybe joining as if I’m joining a new colour and then overlapping as I continue crocheting?