Method of application of neutral sodium fluoride according to Knutson's technique involves all except-
Method of application of neutral sodium fluoride according to Knutson's technique-
If the sodium fluoride reagent is pure and uncontaminated, this solution has a pH of 7. Treatments are given in a series of four appointments. 

At the initial appointment, the teeth are first cleaned with aqueous pumice slurry and then isolated with cotton rolls and dried with compressed  air. Teeth can either be isolated by quadrant or by half mouth. 
Using cotton-tipped applicator sticks, the 2% sodium fluoride solution is painted on the air-dried teeth so that all surfaces are visibly wet. Then  with the teeth still isolated, the solution is allowed to dry for 3 to 4 minutes. 
This procedure is repeated for each of the isolated segments until all of the teeth are treated. 
A  second, third  and  fourth fluoride application, each  not preceded  by a prophylaxis, is scheduled at intervals of approximately one week. 
The four-visit procedure is recommended for ages 3, 7, 11 and 13 years, coinciding with the eruption of different groups of primary and permanent teeth. Thus, most of the teeth would be treated soon after their eruption, maximizing the protection afforded by topical application.
At the initial appointment, the teeth are first cleaned with aqueous pumice slurry and then isolated with cotton rolls and dried with compressed  air.
The sodium fluoride solution applied on the teeth with cotton-tipped applicator stick is allowed to dry for 3 to 4 minutes.
A  second, third  and  fourth fluoride application, each preceded  by a prophylaxis, is scheduled at intervals of approximately one week.
The four-visit procedure is recommended for ages 3, 7, 1 1 and 13 years.