The comma separated data is entered by a user and I want to keep it as simple as possible, so extra quoting is something I want to avoid.

Ok, I see, although there are of course other alternatives. Like for example, it may not be so difficult on the user if you require all fields to be quoted, that's one less rule for the user to remember. In the end, it'll be up to you to decide what is easiest for the user and for the implementation. I agree with AnomalousMonk's point that doubling up the commas leads to ambiguity, so if you really don't like the quoting, perhaps the backslashes are not such a bad idea (and the only issue was really the misunderstandings about the format); the parser I showed here has some pretty simple rules: commas are field separators, backslashes and commas can be escaped with backslashes, plus the support for the \x... sequence.