I've never used RO lump so I can't compare. I have used RO briquettes and they seem to make quite a bit of ash as well and I really didn't care for the smell of them in the UDS. They may act differently in in offset where they are not lighting all the time.. I like the Kingsford Competition Briquettes much better and that is what I use in my UDS.
I can say, without a doubt, that RO briquettes ARE NOT the same as RO lump or any other lump for that matter. If someone told you that, they are, shall we say, misinformed. Lump charcoal is made by taking wood and heating this wood in a closed container in the absence of oxygen. That's why there is very little uniformity to the piece size. It is just wood chunks. Here is a link that has a lot of information about lump charcoal.
http://www.nakedwhiz.com/lumpfaq.htm
Briquettes are a whole different ball game. They have lots of things added to them besides wood. Here is a link that describes the things added to briquettes.
http://virtualweberbullet.com/charcoal.html
Like you said, if you don't have a lot of options, you have to use what you can get. I can get the Kingsford Comp and I really like it. It doesn't have the strange smell that some briquettes have when lighting. It makes very little ash compared to the RO briquettes that I have used. It burns pretty hot, which was a bit of a drawback for me. It took some getting used to to control it in the UDS but I am used to it now and it works really well.
Dave
I can say, without a doubt, that RO briquettes ARE NOT the same as RO lump or any other lump for that matter. If someone told you that, they are, shall we say, misinformed. Lump charcoal is made by taking wood and heating this wood in a closed container in the absence of oxygen. That's why there is very little uniformity to the piece size. It is just wood chunks. Here is a link that has a lot of information about lump charcoal.
http://www.nakedwhiz.com/lumpfaq.htm
Briquettes are a whole different ball game. They have lots of things added to them besides wood. Here is a link that describes the things added to briquettes.
http://virtualweberbullet.com/charcoal.html
Like you said, if you don't have a lot of options, you have to use what you can get. I can get the Kingsford Comp and I really like it. It doesn't have the strange smell that some briquettes have when lighting. It makes very little ash compared to the RO briquettes that I have used. It burns pretty hot, which was a bit of a drawback for me. It took some getting used to to control it in the UDS but I am used to it now and it works really well.
Dave