There are two ways of addressing a Raleigh bottom bracket- with a single, good coating of modern grease, or constant addition of medium weight oil.
In method #1, get a good quality grease. It could be Phil Wood Grease, could be a good lithium grease from the hardware store. The key is that it is a modern, medium viscosity grease with good life. My preference is a decent quality, brown lithium grease from the hardware store. Do not use traditional, thick axle grease. It doesn't last as long and it gums up easily.
In method #2, you oil lubricate with a medium-weight oil. Something like SAE 30 would work in a bottom bracket. In this method, you start by inundating both halves of the bottom bracket with oil. Let it drain out the sides as needed. Every few weeks, add a few drops of oil to keep a certain critical mass of oil in the bottom bracket.
I have used both, and if you can get the bottom bracket apart and cleaned, I prefer #1 because it is much less messy. There should be no need to add oil for quite a long time if you use a decent, modern grease in the bottom bracket. If you add oil, as others have said, eventually the grease thins and washes out and you end up running method #2 by default. Make sure you put cardboard under the bike if you run #2. It will make a mess of your garage floor if you use the oil only method.