Translation:The bread is clean.
Can this sentence be referring to money laundering like in English? Asking for a friend.
Is the pronunciation of the 끗합-part more like 끄카 or rather 끄타? I couldn't guess from hearing but I supposed it should be the latter
The notes in one of the alphabet sections have a chart that describes letters at the end of syllables and what they sound like. According to that chart ㅅ at the end of a syllable, is pronounced like ㅌ unless it's borrowed by the next syllable; which only happens when the next syllable starts with ㅇ. So in 개끗합니다 it's pronounced like 개끝합니다.
The ㅎ also makes a little airy sound, like an h in English, that duo doesn't put across very well.
This is saying the bread is clean. It is like after you wash your hands, they are clean. It is just practice using the adjective with an object we are familiar with.