Excel Numerical Data Formatting Cleanup

I have a spreadsheet of purely numerical records that needs to be put into a clean, analysis-ready state. The core task is to correct every formatting issue—numbers stored as text, misplaced thousand separators, mixed decimal symbols, stray spaces, hidden characters—so each cell ends up as a true numeric value that Excel can calculate with no errors or warnings.

Once the data is standardised, simply return it to me in the same structure (or a clearly documented new sheet if you think that is safer). No deduplication or gap-filling is required this time; the sole focus is formatting accuracy.

Acceptance criteria
• Every entry recognised by Excel as a number (green triangle errors eliminated).
• Consistent decimal and thousand separators across the file.
• No leading/trailing spaces or non-printing characters.
• File opens without conversion prompts or error alerts.

Please include a brief example—or screenshots—of past Excel clean-ups you have completed so I can gauge your approach and turn-around speed. Familiarity with Power Query, VBA or other automation techniques is welcome as long as the final workbook remains lightweight and easy for me to maintain.