---

(Get-Content C:\Scripts\Clear-FirefoxCache.ps1 -Raw) `
  -replace 'Remove-Item -LiteralPath \$t', 'Remove-Item -WhatIf -LiteralPath $t' |
  Set-Content C:\Windows\Temp\dryrun.ps1

powershell -ExecutionPolicy Bypass -File C:\Windows\Temp\dryrun.ps1