Once more unto the breach dear friends, or close the wall up with our English misconceptions, or misinterpretations.
I cannot agree more with you CHokKA, that in its written, and then read form, I could care less means, that if I tried, I could care a little less about something.
I’m saying, that in its articulated, or enunciated form, “I could care less”, particularly when uttered vehemently, conveys a stronger depth of feeling (to me), of what the speaker feels about the subject, he doesn’t want to acknowledge it at all.
I totally recognise your grammar as correct though, as always.