You can do it if you're "good". You need to either pressurize the cylinder to
keep the valves shut or do something like the "rope trick" (feed rope into the
spark plug hole then turn the engine over until it is compressed in the
combustion chamber) Both are a bit risky and you DON'T want to drop a valve
into the cylinder.

How bad would you feel if you DID change all the seals and it didn't make
any difference?

How much oil is the "smoke screen" consuming, and how much does that bother you?

Remember that a vacuum in the cylinder can also pull oil past the rings.

This is a tradeoff you will have to decide for yourself. I doubt if the seals
are of such poor quality that you could pin the rose on them. And you can
see them with the valve cover off, under the valve spring retainers, inside
the spring.

It takes a LOT of oil consumption to (by itself) justify engine work!
--
George Downs Bartlesville, Heart of the USA!