wpaclean: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/wpaclean - from package: aircrack-ng

You may install the required package with command apt-get install {package}

Error in other languages:
wpaclean: bevel nie gevind nie
wpaclean: comandă negăsită
wpaclean: comando não encontrado
wpaclean: commande introuvable
wpaclean: command not found
wpaclean: käsku ei ole
wpaclean: không tìm thấy lệnh
wpaclean: komanda nerasta
wpaclean: Kommando nicht gefunden.
wpaclean: kommandot finns inte
wpaclean: komut yok
wpaclean: nie znaleziono polecenia
wpaclean: níor aimsíodh an t-ordú
wpaclean: no se encontró la orden
wpaclean: no s'ha trobat l'ordre
wpaclean: opdracht niet gevonden
wpaclean: parancs nem található
wpaclean: perintah tidak ditemukan
wpaclean: príkaz nenájdený
wpaclean: příkaz nenalezen
wpaclean: команда не найдена
wpaclean: командата не е открита
wpaclean: 命令找不到
wpaclean: コマンドが見つかりません