that is correct. i liken it to a reverse of say, smoking. they estimate that you lose so many minutes off your life with every cigarette, even though the person does not feel harm at the time. you may not feel benefit at the time of oil pulling, but it will add to your health and longevity incrementally.
always remember, the real power we have over our helath is in lifestyle. it is those things we do (or dont do) every day that create the environment which dictates our health in the future. in other words, people who do not oil pull are as foolish as those who dont quit smoking. i think these are equivalent in effect. its a personal choice which effects the sum total. this is also what makes environmental pollution(indoors and out), personal hygeine products, cleaning produsts, etc so detrimental to health.