Add
deb http://ftp.debian.org/debian experimental main contrib non-free
to your /etc/apt/sources.list
or into /etc/apt/sources.list.d/experimental.list
then execute
apt-get update
apt-get -t experimental install deluge
See Debian Wiki and apt-get
manual
-t, --target-release, --default-release
This option controls the default input to the policy engine; it creates a default pin at priority 990 using the specified release
string. This overrides the general settings in /etc/apt/preferences. Specifically pinned packages are not affected by the value of
this option. In short, this option lets you have simple control over which distribution packages will be retrieved from. Some
common examples might be -t '2.1*', -t unstable or -t sid. Configuration Item: APT::Default-Release; see also the
apt_preferences(5) manual page.