Here's a script to start with.
$path = "c:\temp\zzzz"
$files = Get-ChildItem -Path $path -File -Recurse | Where-Object -Property Extension -eq ""
"We found {0} files." -f $files.count
$files | Remove-Item -whatif
$dirs = Get-ChildItem -Path $path -Directory -Recurse | Sort-Object -Property Fullname -Descending # process subfolders first
foreach ($dir in $dirs) {
$dir.FullName
$contents = Get-ChildItem $dir.FullName
if ($contents.count -eq 0) { # delete empty folders
$dir.FullName
$dir | Remove-Item -WhatIf
}
}