I'd be very surprised if these products weren't identical as " waxoyl " is a registered trademark name.
It was originally marketed by Finnigans before Hammerite sold it.
I've used it for over 30 years on a variety of vehicles and still use it to this day. I have an Opel Manta that I've owned for 34 years and there isn't a bit of rust on it anywhere and I put that down to proper and regular application of Waxoyl.
Sorry but I've got to say that you shouldn't waste your time and money on the manual Waxoyl pump and applicator.
Use a Schutz gun with the flexible extension .
http://cgi.ebay.co.uk/Schutz-Shutz-Underbody-Under-Body-Waxoil-Cavity-Wax-Gun_W0QQitemZ290425895501QQcmdZViewItemQQptZUK_Body_Shop_Supplies_Paint?hash=item439ebb7a4dSet pressure to around 60 - 80 psi for the gun , a little higher when using the extension.
Place the Waxoyl tin in a bucket of HOT water and once it's liquefied ,ie runny , shake the tin to mix it up. Decant some of it into a used Schutz cannister and thin with about 10% white spirit for the gun probably 20% for the extension. Again , shake up the mix . Remember to return the tin to the bucket of hot water and keep topping it up with fresh hot water.
Prior to applying it I always thoroughly pressure wash the vehicle getting all the muck off right into the corners and chassis rails ,spend as much time as you can here as it pays off in the long run. Let the vehicle dry off for a day ( or two ) if you can.
Place a large sheet of builders plastic underneath and then jack it up as high as you can . Wear overalls and an old woolyhat plus goggles . Get the extension of the gun into every nook and cranny that you can and spray away . If you are doing sills and they are longer than the extension do what I did on my Transit and drill holes along the inside inner sill and then use proper rubber grommets to seal up after you've finished.
Do the underside after that but keep it away from brake hoses and brakes in general. The Schutz gun is quite accurate .
ALWAYS remove the door cards and get it right down into the inner doors , if you cant be bothered to remove them find a suitable hole or grommet and insert the flexible extension as far as you can.Rotate the extension slowly as you insert and or withdraw to give 360 deg coverage .
I normally leave it till it starts to go off and then go over it again to ensure a 100% cover . Don't rush the job.
It's actually much much better to do this job in the summer as it will creep only when the ambient temp. is around 16 deg upwards .
I also use a plunger oil can to get into little holes and corners and always use that tool to spray a wetter mix down the inside of the rear arch betweeen the wing and the wheel tub, this slowly seeps into the rear arch lip joint. On the Omega I also use a plunger oil can with a 20% thinned mixture and using a suitable plastic blade get the spout up under the external door window rubbers and apply plenty. If you have an estate apply as much as you can into the cavity where the rear wiper spindle exits. Like the Manta there isn't any sign of rust anywhere on the Omega either.
Use the plunger gun to do behind body trim where there are trim clips through the bodywork.
Best advice I can give you is to set aside as much time as you can and do it properly , as I said it's messy but well worth the effort.
Good Luck
Incidently over here in Ireland I use Car Plan Tetroseal wax / oil which is exactly the same stuff only cheaper.
