Alternative protocol for evaluating RNA integrity, using a bleach gel
I don't think bleach can denature RNA. Bleach is an oxidizing agent and it will damage the RNA. Also, the protocol mentions addition of hypochlorite before heating which I think is illogical because heat will decompose it. 

For testing RNA integrity you need not make a denaturing gel. What you can instead do is to heat the RNA with the 2xRNA loading buffer that contains 95% formamide and run it in a normal TBE/TAE agarose gel. Heating with formamide denatures the RNA permanently. 

Denaturing gels are only essential for Northern Blots. 

You can also run your sample in a bioanalyzer to check for RNA integrity and this is always recommended for RNAseq experiments (even for microarrays but I cannot comment much on that because I have never done it and am not aware of the usual practice).