I am after some advice from experienced wood workers/joiners. I have just bought an older house and had the floors sanded. The problem I have is that there are gaps beneath the skirting boards which are painted white (and will be painted white after the job is done). I want to fill the gaps between the skirtings and the floorboards. Some gaps are quite small but others are as much as about 10 or 12mm. Some of the gaps will be quite deep (well as deep as the skirtings which are around 20mm deep). I am looking for a wood filler that is easy to work with, easy to sand, is flexible and will not shrink. I want to get it right so I don't mind paying a bit extra on this one off job to get it right and dont want to damage the wood floor when applying and sanding (so easily wiped while wet would help!). Also I don't necessarily need a quick drying filler as I would prefer to let it set and then paint rather than rush it. I have read some reviews including Toupret wood filler and Ronseal but the reviews are mixed and dont seem to give me what I am looking for Any experienced tradesman like to give their opinion. Thank you in advance.