For starters the wood dust and glue thing really comes from the flooring trades where they are going to sand the bejaysus out of the floor afterwards (normally starting with a 60 grit and working upwards so any glue spill into open pores won't matter as it'll all be sanded away) and where they can get away with a joint being a different colour. It's sort of become an Internet myth - I see it repeated so often -
but it is so wrong! In work nearer to eye level, such as installed joinery or furniture it will often look absolutely horrendous, so
don't do it
As to 2-pack filler, as Dave points out it'll never be anywhere near a match in colour and will almost always stand out like a sore thumb. As Dave says, the professional approach is to fill any minor cracks with coloured wax. Several colours can be combined to get a near perfect match; for oak this may mean a mixture of medium or dark oak wax, plus maybe a bit of red mahogany (if the timber has a pinkish tinge) or some pine coloured wax if the colour needs to be lighter (and BTW antique pine colour adds yellowness). Bear in mind that all timbers darken and yellow with age, so if it isn't at the 3 to 4 years stage it may have some way to go therefore your filler wax might need to be a tad darker and yellower.
Animal that I am I use a steel stopping knife (with the edges blunted and the sharp corners rounded off) to apply wax - a flexible plastic spatula does just as well for one-offs - and I warm the wax and stopping knife in a mug of hot water for a few minutes before slicing thin curls of wax of the different colours which I then roll into a small ball in the palm of my hand before pushing into the cracks with the stopping knife. Surplus material is scraped off carefully after a few more minutes when it has cooled off, again with the stopping knife (and may be re-used). A quick rub over with a coarse cloth (such as some hessian sacking or a yellow hi-viz vest
) completes the job. Avoid the temptation to use a cold, hard coloured wax block like a child's colouring crayon (another common error) - it just doesn't work that way!
