Multiple keyboards with different layouts in X11

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hello

I try to configure X11 to use two keyboards with different layouts. 
According to xorg.conf(5) using InputClass sections like below should
do it. But X11 does not seems to care. Anyone had some success with that?
Is there some wscons specific trick?

Section "InputClass"
        Identifier  "Build-in keyboard"
        Driver      "kbd"
        #MatchVendor "HAILUCK CO.,LTD"
        #MatchProduct "USB KEYBOARD"
        MatchUSBID  "258a:0021"
        Option      "XkbRules" "evdev"
        Option      "XkbModel" "pc105"
        Option      "XkbLayout" "us"
        Option      "XkbVariant" ",winkeys"
        Option      "XkbOptions" "grp:alt_shift_toggle,terminate_alt_bksp"
EndSection

Section "InputClass"
        Identifier  "Cherry keyboard"
        Driver      "kbd"
        #MatchVendor "Cherry GmbH"
        #MatchProduct "CHERRY Wired Keyboard"
        #MatchUSBID  "046a:c097"
        MatchProduct "CHERRY"
        Option      "XkbRules" "evdev"
        Option      "XkbModel" "macintosh"
        Option      "XkbLayout" "fr"
        Option      "XkbOptions" "grp:alt_shift_toggle,terminate_alt_bksp"
EndSection


-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost