Most rubber, PVC or vinyl dildos tend to smell very strongly due to the nature of the materials and the manufacturing process.
Unfortunately, there is no quick solution to removing this smell, however it should gradually fade if washed regular with warm water and Lovehoney Fresh Toy Cleaner Cleaner (http://www.lovehoney.co.uk/product.cfm?p=25004).
I'm worried about how the toy has now been in contact with essential oils and different cleaning products on top of the toy material itself being sketchy.
The toy is already not particularly safe, and anything you have applied to it could have been absorbed and be put back in your body.
Condoms may not be enough either. Condoms are designed to block biological/viral material, not plasticisers.
We always use a condom on the UR3 type dildos, but for glass or silicone of course you don't need to. My older UR3 dildo smelt worse new than my newer one, but both are fading somewhat now, with regular washing and airing.
We have the same problem with a black rubbery double dildo we have. If oh jses it on me then goes down on me after i can smell it on his face even after he washed his beard! It doesn't really bother me though. X
it is advised that condoms are to be placed over porous material sex toys, before inserting into the body. This will help to prevent nasty bacterias but again, there is only so much cleaning you can do :(