The right command is : echo 0 | tee /proc/sys/net/ipv4/conf/*/send_redirects
Because you must have 0 on 'all' and on 'interface_name' to disable it.
Into /etc/sysctl.conf or similar file, you have to set 'all' + 'default' (or 'all' + 'interface' but the interface may not exists already when this file is processed).
