If you clicked on "Create Schedule" and selected one of the generation methods - Past Timesheet, Past Schedule, or Project Allocations - and decided it wasn't a good fit, all you need to do it go back to "Create Schedule" and click on the red button to clear it.
Clicking on "Clear Suggested Allocations" will remove any of the user project cards that were auto-created by the app, but will NOT delete any cards that you had manually adjusted (if any).
You can tell if you've edited the card by looking at the top right corner of the card. If you notice a shaded corner that means just the suggestion generated.
If the card's allocations have been manually adjusted, meaning hours have been increased or decreased then the corner flag will not be there.
Because we don't overwrite any "human" changes to allocations, any cards that you have increased or decreased the hours on will remain despite clearing or regenerating the dashboard.
To delete those on the subtraction sign in the allocation wheel until the red "x" appears.