Dishonest person, identifiable by floating? (6)

I believe the answer is:

badegg

I'm a little stuck... Click here to teach me more about this clue!

'identifiable by floating?' is the definition.
I know nothing about this answer so I can't tell whether this works.

'dishonest person' is the wordplay.
'dishonest' becomes 'bad' (I can't explain this - if you can you should believe this answer much more).
'person' becomes 'egg' (as in 'a bad egg').
'bad'+'egg'='BADEGG'

Can you help me to learn more?

I've seen this clue in The Daily Express.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.