Use com moderaçao, procure saber o que ele faz antes lendo o script ok.

#Limpar mac zerado
:foreach i in=[/ip dhcp-server lease find mac-address=00:00:00:00:00:00] do={
:log error ("Mac address zero detectado: " . [/ip dhcp-server lease get $i address]);
/ip dhcp-server lease remove $i;
}

# Limpar entradas Busy
:foreach i in=[/ip dhcp-server lease find status="busy"] do={
:log error ("Busy status detectado: " . [/ip dhcp-server lease get $i address]);
/ip dhcp-server lease disable $i;
/ip dhcp-server lease enable $i;
}

# Limpar entradas Android (uso em redes publicas)
:foreach i in=[/ip dhcp-server lease find host-name~"android"] do={
:log error ("Removendo entradas android: " . [/ip dhcp-server lease get $i address]);
/ip dhcp-server lease remove $i;
}

# Limpar quando hostname esta vazio
:foreach i in=[/ip dhcp-server lease find host-name=""] do={
:log error ("Removendo entradas em branco sem hostname: " . [/ip dhcp-server lease get $i address]);
/ip dhcp-server lease remove $i;
}

Valewz