Another Straightforward 4-letters Crossword?

Question

_{This is an entry for Fortnightly Topic Challenge #43: Variety Crossword Grids.}

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Across
4. "___ and on"
5. "La ___" light
6. Aside from it
8. Diagonal
10. Firefly
12. Clothes shop
14. Supersede
16. -ism or -y
18. Area in Da Nang
21. "___ many times do..."
22. Dad and son
23. From readers

Down
1. Strange word
2. "Diana" son
3. Analyze
5. (lit.) Fish
7. Ideal closed
9. "I Agree" (Sumo)
11. Rope's end
13. "These are ___ times"
15. "Perry Mason"?
17. Should be
19. Aid of a sort
20. An angry act

The final answer will be a 4-words phrase.

Answer 1

The trick to this puzzle is that

the clues are completely unsolvable!

So what do you do?

You might start to notice some repetitions - "These are ___ times", and "___ many times do...", for instance. Or maybe you notice that "son" ends both Dad and son and "Perry Mason"?.

So, instead of entering answers into the grid, you enter the clues into the grid! Some letters have to be squeezed into the same cell, but there is a unique way to do this.

The filled grid:

And now, for the final answer,

since this is a "4-letters crossword"< look at all the cells that have exactly four letters. Top to bottom, these spell out the answer: STRAIGHT FROM THE SHOULDERS, which is an expression meaning "honest" or "straightforward".