What must be used to apply powder on patrons?

Using cotton or sanitized applicators to apply powder on patrons is the correct approach because it ensures hygiene and minimizes the risk of contamination. When applying products directly from a container or using bare hands, there is a significant chance of transferring bacteria, oils, or other impurities to the patron's skin. This can lead to adverse reactions or infections.

Sanitized applicators maintain a clean application method, allowing for an even distribution of the powder while also protecting the health and safety of both the patron and the practitioner. This practice is important in maintaining the standards of cleanliness and sanitation required in any setting where personal care or cosmetics are applied.

Utilizing old makeup brushes or any available tool without assurance of sanitation can increase the likelihood of unsanitary conditions and compromise the quality of the application. Therefore, the use of appropriate, sanitized materials is paramount in any hygiene-conscious environment.