Trying to blacklist a USB memory stick

["Bruen, Mark" <mbruen@trilegiant.com>]

I'm trying to blacklist a USB memory stick in /etc/multipath.conf. The 
output of multipath -v4:
===== path sdar =====
bus = 1
dev_t = 66:176
size = 126976
vendor =        
product = USB DISK 2.0   
rev = 1.16
h:b:t:l = 3:0:0:0
tgt_node_name =
failed to open /dev/sdar

I've tried this with the "h:b:t:l" alone and with the "product" alone 
(neither work):

devnode_blacklist {
#   devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st|sda|sdb|hdc)[0-9]*"
    devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st|hdc)[0-9]*"
    devnode "sda "
    devnode "sdb "
    wwid 350002ac0001302c6
    wwid 350002ac0002502c6
    device {
        h:b:t:l = 3:0:0:0
        product "USB DISK 2.0"
    }
}

Any ideas? Thanks.
-Mark