Certain criteria would need to be met by any additive to repel sniffers.
Thirdly, it must not cause the sniffer to vomit.
It seems that glue is regarded as safe to sniff and as causing no lasting damage to the health of the sniffer.
Determined sniffers will sniff despite the law and others will consider it a challenge to be defied.
There were checks of vehicles by "sniffer" dogs trained to detect materials used in the manufacture of explosive devices.
One of the ways of detecting drugs going into prisons is increased use of sniffer dogs.
These include: searching of staff, the use of sniffer dogs and setting up intelligence systems.
Certainly no sniffer dogs appear to be available.