A technician said: Its better to use a solid cables for homes (not stranded cables).

I did not use any calculations but I think that stranded cables are better due to skin effect. We use 220V / 50Hz.

Is 50Hz too low frequency so that we can consider it as DC and "skin effect" has a very small effect at that frequency?

Is there any factors other than "skin effect" so that he recommends solid cables?

I'm speaking about cable that have 10 mm sq at most. And length is less than 20 m.

Thank you,