Attention: this also disables communication with xfconfd, thunar will start with default settings !
Start thunar without gvfs support:
export DBUS_SESSION_BUS_ADDRESS= ./thunar/thunar -q;./thunar/thunar
re-enable gvfs:
export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
More information on how gvfs is used in thunar can be found on this bug: https://bugzilla.xfce.org/show_bug.cgi?id=14812