Convert Comma-Separated URLs to List Column in Clay

I have a column that contains a comma-separated list of URLs (e.g. https://a.com,https://b.com). I need to convert this into a true List column so I can run an enrichment once per URL. The Formula Generator keeps emitting JSON.stringify or JS-style output, and the result remains a string instead of a list. What is the recommended Clay-native way (Formula, Transform, or other) to reliably split a comma-separated string into a List column suitable for looping enrichments? And is there a preferred method to trim whitespace during the split?