I think the intent is /sɝks/, rhymes with "lurks" /lɝrks/, with the r-colored vowel in General American, but perhaps the author speaks with a non-rhotic dialec

I think the intent is /sɝks/, rhymes with "lurks" /lɝrks/, with the r-colored vowel in General American, but perhaps the author speaks with a non-rhotic dialect. But that makes it sound like something between "sex" "sacks" and "sucks", which is less flattering.