Rule 1. When correcting people's grammar, make sure you use correct grammar.
Actually "more clear" is a correct form of the comparative depending on the sentence structure and it's usage. When I said that Mind-numbed Robot could "not be more clear than that", then the usage in that sentence was perfectly acceptable grammar. Since there is no grammatical substitute for "less clear" than "less clear" then "more clear" is clearly acceptable grammar.
From a website discussing this issue:
Comparatives in English are all replacements for the standard "more". There are very few occasions when a descriptive adjective cannot use the "more" form (one of which is when you are already using a comparative, i.e. something can't be "more smaller").
However, more common in usage is to use the -er form, "clearer". Of course, when modifying a verb, the adverb form must be used ,"more clearly".
"Can I make the meaning clearer?" = "Can I make the meaning more clear?"
So have I made my point clear, or should I try to make my point even more clear?