They aren’t the same.

살 /sal/ “meat” is pronounced with [sʰ]. It’s roughly like the “ssh” in “grasshopper”.

쌀 /s͈al/ “uncooked rice” uses [s͈] instead. It’s a “tense” consonant; if I got it right the main difference is faucalised voice, you’re supposed to lower the larynx a bit while speaking it.

Since the difference yields different words, they’re a minimal pair so they aren’t allophones but different phonemes. If you speak Korean (I don’t) the difference between those two is on the same level as the one between English “bot” vs. “pot”, or between “bit” and “beet”. However since the contrast isn’t common out there they sound similar for non-speakers, and I think this to be what OP is trying to convey.